Type of heat transfer of dryers / conductive heat transfer / sludge drying, slurry drying, feed drying

About conductive heat transfer
Conductive heat transfer is to heat materials through an object, such as a board, and the materials are heated and dried by the conductive heat transferred via the heated board.
Convective heat transfer drying heats materials directly, however, conductive heat transfer drying heats materials via an object such as metal board. So that convective heat transfer is sometimes called direct heating and conductive heat transfer is called indirect heating.Conductive heat transfer has higher thermal efficiency than convective heat transfer since the amount of exhausted gases is smaller.
In case that there are risks of scattering, oxidation or explosion of the material by using hot blast in convective heat transfer, this conductive heat transfer will be more suitable.To improve drying speed, good contact between material and heating board is important and better method such as agitation, mixing, or contacting the material to the heating board thinly and widely, should be thought out.
KENKI DRYER is a dryer using this conductive heat transfer, indirect heating method.One of the characteristics of KENKI DRYER is a unique structure of blade which forces to scrap off the adhered materials and prevent clogging inside of the dryer, however, this structure is also one of the reasons for improving its drying efficiency since the materials to be dried can be agitated sufficiently.
Please see this for the details of the self-cleaning screw.